NAME¶
RAND_load_file, RAND_write_file, RAND_file_name - PRNG seed file
SYNOPSIS¶
#include <openssl/rand.h>
const char *RAND_file_name(char *buf, size_t num);
int RAND_load_file(const char *filename, long max_bytes);
int RAND_write_file(const char *filename);
DESCRIPTION¶
RAND_file_name() generates a default path for the random seed file.
buf points to a buffer of size
num in which to store the
filename. The seed file is $RANDFILE if that environment variable is set,
$HOME/.rnd otherwise. If $HOME is not set either, or
num is too small
for the path name, an error occurs.
RAND_load_file() reads a number of bytes from file
filename and
adds them to the PRNG. If
max_bytes is non-negative, up to to
max_bytes are read; starting with OpenSSL 0.9.5, if
max_bytes is
-1, the complete file is read.
RAND_write_file() writes a number of random bytes (currently 1024) to
file
filename which can be used to initialize the PRNG by calling
RAND_load_file() in a later session.
RETURN VALUES¶
RAND_load_file() returns the number of bytes read.
RAND_write_file() returns the number of bytes written, and -1 if the
bytes written were generated without appropriate seed.
RAND_file_name() returns a pointer to
buf on success, and NULL on
error.
SEE ALSO¶
rand(3),
RAND_add(3),
RAND_cleanup(3)
HISTORY¶
RAND_load_file(),
RAND_write_file() and
RAND_file_name()
are available in all versions of SSLeay and OpenSSL.